Don't let the habitat fool you. You might think that a rural setting has less cars and less opportunties for troubles, but they just face different obstacles. Cats have been domesticated, just like humans. Most people could not adapt to living in caves, and cats are the same.   Besides territorial battles with other cats, there are other predators, ticks and exposure to other dangers when they are allowed to roam free outdoors. You are being cruel when you keep a cat indoors - in fact most modern vets would argue the opposite.